Left atrial volumetric remodeling is predictive of functional capacity in nonobstructive hypertrophic cardiomyopathy
ABSTRACT The left atrium is afterload sensitive, responding to immediate changes in left ventricular (LV) diastolic pressure, and left atrial volumetric remodeling has been reported in conditions associated with abnormal diastolic function. We examined the relationship between left atrial volumetric remodeling and objective measures of exercise capacity in patients with nonobstructive hypertrophic cardiomyopathy (HCM).
We compared LA volume indices, other 2-dimensional and Doppler echocardiographic parameters, invasive hemodynamic measures, and magnetic resonance imaging (MRI)-derived LV mass with exercise duration, maximal oxygen uptake (MV* O2), anaerobic threshold (AT), and ventilatory efficiency (VE/V* CO2 slope) in 43 patients with nonobstructive HCM. Patients underwent cardiac catheterization within 48 hours and metabolic stress testing within 1 week of their echocardiogram and MRI examinations.
Left atrial volume at end-ventricular systole (LA max) and end-atrial emptying (LA min) correlated with MV* O2 (r = -0.39, P < .01 for both), AT (r = -0.42, r = -0.39, respectively, P < .01 for both), and VE/V* CO2 slope (r = 0.45, P = .003; r = 0.41, P = .008). Patients with an LA max > or =33 mL/m2 had significantly lower MV* O2 (P = .025) and AT levels (P = .017) and higher VE/V* CO2 slope levels (P = .004) as compared with patients with a smaller LA size. In multivariate analysis, MRI-determined LV mass, which was not a univariate correlate of exercise tolerance, provided additional effect when combined with LA volume index.
Left atrial volumetric remodeling predicts exercise capacity in nonobstructive HCM and may reflect chronic LV diastolic burden. This simple noninvasive measure of LA size may provide a long-term indication of the effects of chronically elevated filling pressures in patients with HCM and further studies testing its prognostic value are necessary.
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ABSTRACT: Our aim was to examine the association between the extent of late gadolinium enhancement (LGE) at right ventricular insertion points (RVIP) and left ventricular (LV) functional parameters in patients with hypertrophic cardiomyopathy (HCM). Sixty-one HCM patients underwent echocardiography and cardiovascular magnetic resonance (CMR) within one week. Mitral annular velocities (E/E') were obtained from echocardiography; LV ejection fraction (EF), LV mass index, LV wall maximal thickness, and left atrial volume index (LAVI) were obtained from MR. LGE extent was quantified (proportion of total LV myocardial mass) according to location: % RVIP-LGE and % non-RVIP-LGE. Although LGE was commonly present in both apical (74 %) and non-apical HCMs (88 %) (p = 0.163), RVIP-LGE was more frequent (86 % vs. 47 %, p = 0.002) in non-apical HCMs in which E/E' was significantly higher (19.23 ± 8.40 vs. 13.13 ± 5.06, p = 0.009). In addition, RVIP-LGE extent was associated with LV diastolic dysfunction (r = 0.45, p < 0.001 for E/E'; r = 0.53, p < 0.001 for LAVI) and lower LVEF (r = -0.42, p = 0.001). There was no correlation between non-RVIP-LGE extent and other parameters. Multiple linear regression analysis revealed RVIP-LGE extent as an independent predictor of E/E' (β = 0.45, p < 0.001) and LAVI in HCM patients (β = 0.53, p < 0.001). The extent of LGE at RVIPs in HCM patients is associated with increased estimated LV filling pressure and chronic diastolic burden. • Late gadolinium enhancement at RV insertion points is frequently seen in HCM. • RVIP-LGE extent is correlated with increased estimated LV filling pressure in HCM. • Non-RVIP-LGE extent did not show any association with LV diastolic dysfunction.European Radiology 01/2015; 25(4). DOI:10.1007/s00330-014-3390-8 · 4.34 Impact Factor
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ABSTRACT: We sought to evaluate the relation between atrial fibrillation (AF) and the extent of myocardial scarring together with left ventricular (LV) and atrial parameters assessed by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM). AF is the most common arrhythmia in HCM. Myocardial scarring is also identified frequently in HCM. However, the impact of myocardial scarring assessed by LGE CMR on the presence of AF has not been evaluated yet. 87 HCM patients underwent LGE CMR, echocardiography and regular ECG recordings. LV function, volumes, myocardial thickness, left atrial (LA) volume and the extent of LGE, were assessed using CMR and correlated to AF. Additionally, the presence of diastolic dysfunction and mitral regurgitation were obtained by echocardiography and also correlated to AF. Episodes of AF were documented in 37 patients (42%). Indexed LV volumes and mass were comparable between HCM patients with and without AF. However, indexed LA volume was significantly higher in HCM patients with AF than in HCM patients without AF (68 +/- 24 ml.m-2 versus 46 +/- 18 ml.m-2, p = 0.0002, respectively). The mean extent of LGE was higher in HCM patients with AF than those without AF (12.4 +/- 14.5% versus 6.0 +/- 8.6%, p = 0.02). When adjusting for age, gender and LV mass, LGE and indexed LA volume significantly correlated to AF (r = 0.34, p = 0.02 and r = 0.42, p < 0.001 respectively). By echocardiographic examination, LV diastolic dysfunction was evident in 35 (40%) patients. Mitral regurgitation greater than II was observed in 12 patients (14%). Multivariate analysis demonstrated that LA volume and presence of diastolic dysfunction were the only independent determinant of AF in HCM patients (p = 0.006, p = 0.01 respectively). Receiver operating characteristic curve analysis indicated good predictive performance of LA volume and LGE (AUC = 0.74 and 0.64 respectively) with respect to AF. HCM patients with AF display significantly more LGE than HCM patients without AF. However, the extent of LGE is inferior to the LA size for predicting AF prevalence. LA dilation is the strongest determinant of AF in HCM patients, and is related to the extent of LGE in the LV, irrespective of LV mass.Journal of Cardiovascular Magnetic Resonance 09/2009; 11(1):34. DOI:10.1186/1532-429X-11-34 · 5.11 Impact Factor
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ABSTRACT: Heart transplant (HT) recipients demonstrate limited exercise capacity compared to normal patients, very likely for multiple reasons. In this study we hypothesized that left atrial volume (LAV), which is known to predict exercise capacity in patients with various cardiac pathologies including heart failure and hypertrophic cardiomyopathy is associated with limited exercise capacity of HT recipients. We analyzed 50 patients [age 57 ±2 (SEM), 12 females] who had a post-HT echocardiography and cardiopulmonary exercise test (CPX) within 9 weeks time at clinic follow up. The change in LAV (ΔLAV) was also computed as the difference in LAV from the preceding one-year to the study echocardiogram. Correlations among the measured parameters were assessed with a Pearson's correlation analysis. LAV (n = 50) and ΔLAV (n = 40) indexed to body surface area were 40.6 ± 11.5 ml·m-2 and 1.9 ± 8.5 ml·m-2·year-1, data are mean ± SD, respectively. Indexed LAV and ΔLAV were both significantly correlated with the ventilatory efficiency, assessed by the VE/VCO2 slope (r = 0.300, p = 0.038; r = 0.484, p = 0.002, respectively). LAV showed a significant correlation with peak oxygen consumption (r = -0.328, p = 0.020). Although our study is limited by a retrospective study design and relatively small number of patients, our findings suggest that enlarged LAV and increasing change in LAV is associated with the diminished exercise capacity in HT recipients and warrants further investigation to better elucidate this relationship.Journal of Cardiothoracic Surgery 11/2010; 5:113. DOI:10.1186/1749-8090-5-113 · 3.05 Impact Factor